1. Technical Field
The system is directed to the field of infotainment systems. More particularly, this system provides a way to provide personalized content to a user while reducing the active control of the system by the user.
2. Related Art
Infotainment systems are well known in the art and are widely used for various purposes. Generally, infotainment systems are used for providing information to the user. The information provided to the user may be stored in the infotainment system (such as a motion picture on a Digital Versatile Disc), may be received by the infotainment system from other sources (such as a broadcasted radio or television program), or may be generated by the infotainment system based on certain input data such as time of the day, current location, or the like (such as a portable navigation device). The information is typically provided to the user in acoustic form, in visual form, or in a combination thereof.
There is a need for providing infotainment systems that are adapted to the specific needs of the driver or the passenger of a vehicle such as an automobile. During long journeys the driver and the passengers desire to be entertained by being provided with information. The driver in particular may be supported by information such as navigation instructions that are provided by the infotainment system.
A disadvantage of prior art systems is the inflexibility in personalizing content and entertainment for one or more users. The current state of the art comprises predefined radio stations or content providers/sources that are programmed remotely. These stations have a particular programming format or genre and are rigid in structure. They currently cannot be personalized in any way by the user/consumer for in-vehicle consumption. The listener can choose among these stations/sources, but once a station is selected, the user is captive to the play list of that station or source.
Whereas conventional analog radio provided at most a few tens of different receivable stations, the number of available channels has multiplied about tenfold with the introduction of digital audio broadcasts in particular with the introduction of satellite-based digital radio services (Satellite Digital Audio Radio Service, SDARS). Another increase by a factor of ten is to be expected with the advent of in-car Internet connectivity allowing a user to access thousands of Internet radio stations.
There is a large variety of competing digital audio broadcasting systems, which differ with respect to transmission technology (terrestrial versus satellite-based systems, systems adapted for mobile or stationary receivers, modulation schemes, frequency bands, etc.), coding methods (systems employing proprietary or open standards, different codecs and encryptions), and business models (free radio systems, subscription-based content delivery, pay-per-item or download). Most of the satellite-based systems, for instance, are proprietary, using different codecs for audio data compression, different modulation techniques, and/or different methods for encryption and conditional access.
Common to all digital audio broadcasting systems is that digital audio information is transmitted in compressed form in order to economize transmission bandwidth and/or to improve transmission quality. Lossy data compression is achieved by employing a psychoacoustic model of the human auditory system to decide what information can be neglected without adversely affecting the listening experience. Coding and decoding of the audio information is performed by methods collectively termed codecs. Prominent examples of codecs employed in connection with digital audio broadcasting are MUSICAM (Masking pattern adapted Universal Subband Integrated Coding And Multiplexing), AAC (Advanced Audio Coding), and MP3, more precisely referred to as MPEG-1 Audio Layer 3 (Motion Picture Expert Group).
MP3 for instance, is a popular digital audio encoding and lossy compression format, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. It provides a representation of pulse-code modulation-encoded audio in much less space than straightforward methods, by using the above-mentioned psychoacoustic models to discard components less audible to human hearing, and recording the remaining information in a highly efficient manner based on entropy coding schemes. MP3 audio can be compressed with several different bit rates, providing a range of tradeoffs between data size and sound quality.
An MP3 file is made up of multiple independent MP3 frames which consist of the MP3 header and the MP3 data. This sequence of frames is called an elementary stream. The MP3 data is the actual audio payload. The MP3 header consists of a sync word, which is used to identify the beginning of a valid frame, followed by a bit indicating that this is the MPEG standard and two bits that indicate that layer 3 is being used, hence MPEG-1 Audio Layer 3. After this, the values will differ depending on the MP3 file. The range of values for each section of the header along with the specification of the header is defined by ISO/IEC 11172-3.
In addition to the proper audio data, most digital audio broadcasting systems also transmit program-associated data (PAD or meta data) with the artist and title of each song or program, and possibly the name of the channel. The meta data may for instance be decoded by the receiver for channel identification and display purposes.
MP3 files, for instance, may contain ID3 meta data containers (ID3v1 and ID3v2) which precede or follow the MP3 frames. These meta data containers allow information such as title, artist, album, track number, or other information about the file to be stored in the file itself.
The ID3v1 container occupies 128 bytes, beginning with the string TAG. The small container size only allows for 30 bytes for the title, artist, album, and a “comment”, 4 bytes for the year, and a byte to identify the genre of the song from a list of 80 predefined values. On the other hand, ID3v2 tags are of variable size, and are usually positioned at the start of a file in order to facilitate streaming. They consist of a number of frames, each of which contains a piece of meta data. Frames can be 16 MB in length.
In the latest ID3v2 standard there are 84 predefined types of frame. In particular, there are standard frames for containing title, cover art, copyright and license, lyrics, arbitrary text, and URL data, as well as other information. The TIT2 frame, for example, contains the title, and the WOAR frame contains the URL of the artist's website.
Digital audio broadcasting systems generally “stream” the audio data to their clients. Streaming media is media that is consumed (heard or viewed) while it is being delivered—just as the traditional analog broadcasting systems, but in contrast to certain Internet content providers, which require a complete download of a file prior to playing it.
Satellite Digital Audio Radio Service (SDARS), for instance, is a satellite based radio system for broadcasting CD-like music and talk shows to mobile and fixed receivers. SDARS is operated in North America by two providers, XM Radio and Sirius Radio, which intend to offer approximately 100 channels. Each provider has launched satellites in either a geostationary or a highly elliptical orbit in order to relay the broadcast signal from a ground station.
SDARS operates in the 2.3-GHz S band, i.e. from 2320 to 2345 MHz. SDARS receivers are able to directly receive the satellite's line-of-sight signals via small-sized antennas. Terrestrial repeaters retransmit the signals in areas that are prone to weak signals, due to overhead obstructions like tall buildings in downtown areas. The SDARS receivers are designed to receive one or two of the satellite signals and the non-line-of-sight signals from terrestrial repeaters.
SDARS requires the user to subscribe to the provider's service. This is facilitated in that each SDARS receiver has an Electronic Serial Number (ESN)—Radio ID to identify it. When a unit is activated with a subscription, an authorization code is sent in the digital stream telling the receiver 100 to allow access to the blocked channels.
An example for a terrestrial digital radio technology is HD Radio, which has been selected by the Federal Communications Commission (FCC) as the standard for local area broadcasts within the United States. HD Radio offers multiple programs with CD quality on one channel and operates on the same frequencies allocated to analog (FM and AM) radio stations.
HD Radio is short for Hybrid Digital Radio, referring to the fact that analog and digital signals are transmitted simultaneously on the same channel. In hybrid mode, a conventional AM or FM signal is transmitted at the channel's center frequency whereas the digital signal is transmitted at the sidebands.
Digital Audio Broadcasting (DAB) is the European counterpart to HD Radio in the United States. DAB has been designated as the follow-up system for the conventional analog radio and uses the frequency bands III (174-230 MHz) L (1452-1492 MHz).
Finally, Internet radio is also a form of digital audio broadcast growing more and more popular. Broadcasting on the Internet is usually referred to as netcasting since it is delivered over a network and not transmitted broadly. In contrast to the above digital audio broadcasting systems, the transmission method is thus not specified, but may for example be WLAN or UMTS.
With a conventional radio it is not possible to select the music you want to hear but rather search for music on the various channels in a manual fashion. With the advent of the various forms of digital radio broadcasting, the number of receivable channels is ever increasing. Given the enormous number of digital radio channels that can be received via satellite, terrestrial broadcasting stations, and the Internet, selecting music that you want to hear is a manually intensive effort.
Especially in cars, digital communication capabilities are expected to become more and more ubiquitous in the near future. Therefore, modern in-car entertainment systems will not only comprise conventional receivers for free radio and subscription based media providers such as SDARS, but also bidirectional communication links for music downloads and Internet radio. With all this content it is very difficult to have a structured listening experience that allows the user to listen to preferred music during each trip.
Studies have shown that interaction with devices in the vehicle, such as cell phones, can increase the risk of accidents. It will be important to have a scheme for allowing personalization of content selection while simplifying management and selection of content.